In logic and semantics, the term statement is variously understood to mean either: a meaningful declarative sentence that is true or false,[citation needed]...

A conditional statement may refer to: A conditional formula in logic and mathematics, which can be interpreted as: Material conditional Strict conditional...

In logic and mathematics, the converse of a categorical or implicational statement is the result of reversing its two constituent statements. For the...

In philosophy and logic, the classical liar paradox or liar's paradox or antinomy of the liar is the statement of a liar that they are lying: for instance...

First-order logic, also called predicate logic, predicate calculus, or quantificational logic, is a collection of formal systems used in mathematics,...

1921, borrowing from rhetoric, where a tautology is a repetitive statement. In logic, a formula is satisfiable if it is true under at least one interpretation...

of deriving conclusions from premises. They are integral parts of formal logic, serving as norms of the logical structure of valid arguments. If an argument...

Paraconsistent logic is a type of non-classical logic that allows for the coexistence of contradictory statements without leading to a logical explosion...

Modal logic is a kind of logic used to represent statements about necessity and possibility. In philosophy and related fields it is used as a tool for...

proposition is a central concept in the philosophy of language, semantics, logic, and related fields, often characterized as the primary bearer of truth...

requestors simultaneously. Such a statement can conveniently be expressed in a temporal logic. Consider the statement "I am hungry". Though its meaning...

Paraconsistent logic – Type of formal logic without explosion principle Paradox – Logically self-contradictory statement Tautology – In logic, a statement which...

Classical logic Computability logic Deontic logic Dependence logic Description logic Deviant logic Doxastic logic Epistemic logic First-order logic Formal...

imperative programming language Statement (logic and semantics), declarative sentence that is either true or false Statement, a declarative phrase in language...

is a logically self-contradictory statement or a statement that runs contrary to one's expectation. It is a statement that, despite apparently valid reasoning...

or disproved, and depends on its logical form. In logic, an argument is a set of related statements expressing the premises (which may consists of non-empirical...

branch of logic. It is also called propositional logic, statement logic, sentential calculus, sentential logic, or sometimes zeroth-order logic. Sometimes...

of bivalence is studied in philosophical logic to address the question of which natural-language statements have a well-defined truth value. Sentences...

In logic and mathematics, contraposition, or transposition, refers to the inference of going from a conditional statement into its logically equivalent...

propositional logic, the double negation of a statement states that "it is not the case that the statement is not true". In classical logic, every statement is logically...

basis that, in traditional systems of logic (e.g., classical logic and intuitionistic logic), every statement becomes a theorem if a contradiction is...

In logic, contingency is the feature of a statement making it neither necessary nor impossible. Contingency is a fundamental concept of modal logic. Modal...

the work of Andrzej Mostowski and Per Lindström. In a first-order logic statement, quantifications in the same type (either universal quantifications...

Mathematical logic is the study of formal logic within mathematics. Major subareas include model theory, proof theory, set theory, and recursion theory...

In logic, a predicate is a symbol that represents a property or a relation. For instance, in the first-order formula P ( a ) {\displaystyle P(a)} , the...

In logic, a three-valued logic (also trinary logic, trivalent, ternary, or trilean, sometimes abbreviated 3VL) is any of several many-valued logic systems...

be truth functional. Classical propositional logic is a truth-functional logic, in that every statement has exactly one truth value which is either true...

In logic, the logical form of a statement is a precisely specified semantic version of that statement in a formal system. Informally, the logical form...

In mathematics and formal logic, a theorem is a statement that has been proven, or can be proven. The proof of a theorem is a logical argument that uses...

Tautology (language), a redundant statement in literature and rhetoric Tautology (logic), in formal logic, a statement that is true in every possible interpretation...